The earth is roughly 70% water, with 96% of this water being ocean. The sea seems like a whole other world away from our own habitat yet 80% of marine pollution comes from the land we live on. We are literally spilling over our land into our fragile waters; killing off marine life, destroying coral reefs and generally treating the ocean as a dumping ground for waste. This not only affects life within the ocean but also ourselves, with a great amount of the pollution subsiding in coastal waters, and toxic waste passing into the food chain of seafood, or killing off lower parts of the food chain, which in turn, starves the predators of many animals, creating an ongoing cycle.
Non-point source pollutants occur from land run off, which is the largest cause of ocean pollution. These types of pollutants can be overlooked due to their form and size; they don’t appear as obvious as a large oil spill, but the small amounts result in massive environmental impacts. Fertilizers from farms for example, will work their way into streams and creeks, running off into rivers and oceans. These nutrients that are discharged into the water result in eutrophication, causing a stimulation in the growth of algae. Algal blooms starve the water of oxygen and block sunlight from reaching marine plants; killing off life, and in extreme cases, creating dead zones in our ecosystems.
Sewage pollution also results in eutrophication, as well as transmitting and spreading disease-causing bacteria around our coastlines. Sewage carries excess nutrients, and the organic material that is present in human sewage requires a great amount of oxygen to decompose the pollutants. The greater the amount of organic material present creates a greater amount of oxygen needed to decompose these pollutants, which again, results in high levels of oxygen depletion. Sewage treatment varies in urban areas, with many cities having little to no treatment, which is worsening with population growth. Leaking, broken or blocked pipes and sewage systems flow to our water sources, with the speed of the process increasing when flooding occurs.
Oil spills are very fatal to life in the ocean; internally damaging or choking animals and affecting their ability to regulate their body temperature or float on the water. Oil can also remove the animals scent in which parents use to trace their young, causing them to starve to death. Due to its density, oil does not dissolve in water but floats on the surface, blocking all sunlight for aquatic plants that photosynthesise, damaging the whole ecosystem.
Unbelievably, rubbish dumping in the ocean was accepted until the 1970’s. Collection of marine debris such as the Great Pacific Garbage Patch (as well as other large areas of ocean ‘landfill’) exposes the frightening reality; our oceans are suffering and are becoming near impossible to clean, with the debris being so broken down it is nearly microscopic. Birds mistake this debris for food, digesting it and causing them to slowly starve to death. Animals can also become entangled in litter such as excess fishing lines, six-pack rings and packing bands, which can cut off their circulation and airways.
These are only a few issues of water pollution that are happening today. They are all very real and are causing severe damage to our ecosystems which will become irreversible. Educating people about these issues is the first step in broadening an understanding, so we can work together to reduce the levels of pollutants and save our oceans.